Fluid sampling device

ABSTRACT

A fluid sampling device which is capable of delivering a sample of fluid in a closed, dry vessel which is free of contaminants on its outside surfaces. The sampling device is adapted to be inserted into the fluid flow system to assure sampling accuracy and to be completely withdrawn to leave the system undisturbed and unobstructed between sampling operations. The sampling device is so constructed that its operation is not inhibited by solid material in the fluid.

United States Patent [191 McCo Oct. 16, 1973 FLUID SAMPLING DEVICEPrimary ExaminerS. Clement Swisher [76] Inventor: James L. McCoy, CapNegret l9, Attorney' olsen & Stephenson Altea, Spain [22] Filed: Dec.20, 1971 [57] ABSTRACT [21] Appl. No.: 209,948 A fluid sampling devicewhich is capable of delivering a sample of fluid in a closed, dry vesselwhich is free 52 .S. of Contaminants on its Outside surfaces Thesampling g 8' 2 412 7 device is adapted to be inserted into the fluidflow system to assure p g accuracy and to be completely [58] Field ofSearch 73/422 TC withdrawn to leave the System undisturbed and unob [56]References Cited structed between sampling operations. The samplingdevice is so constructed that its operation is not inhib- UNITED STATESPATENTS ited by solid material in the fluid. 3,084,555 4/1963 Van Dop73/422 9 Claims, 5 Drawing Figures PATENTEnnm 161975 3.765 246 SHEET 1BF 2 I Z -/o FLUID SAMPLING DEVICE BACKGROUND OF THE INVENTION Intreatment plants for waste or fresh water, continuous control of theprocess variables is essential to assure economy, quality, anduniformity in the process. Proper control of the treatment process canonly be assured if accurate samples of the fluids in process can becollected. The collection of representative samples from various pointsin the treatment systems may be a difficult task due to the nature ofthe contents of the system. Many fluids encountered in sampling are notonly unpleasant but are unsafe to handle.

The prior art is divided into dipper-type samplers for non-pressurizedsystems and valve-type samplers for pressurized and non-pressurizedsystems. The dippertype sampler depends on gravity for its operation andhas drawbacks due to the likelihood of the dipper and the samplebecoming contaminated. The dipping action tends to disturb the systemand thus reduce the repeatability of sampling. Where valve-type samplersare utilized, the valve is merely opened and fluid is allowed to flowout into a receptacle in response to pressure differentials. Thequantity of the sample is dependent on the system pressure and theconsistency of the fluid sampled. Both parameters may fluctuate duringprocessing. The valve is also susceptible to clogging when solidmaterial is present. Eddy currents may be created by the flow at thevalve inlet which would disturb the system and possibly yield erroneoussamples.

SUMMARY OF THE INVENTION The present invention is suitable for bothpressurized and nonpressurized systems and'overcomes the objections ofthe prior art.

A slidable piston assembly is mounted in a bore which communicates withthe system to be sampled. The piston assembly reciprocates from aretracted position. to a sampling position and back during operation.The piston assembly has a sealing cylinder nested inside a concentricplunger. A cylindrical vessel of a given volume with a cylindrical coveris nested inside the concentric sealing cylinder. All the contiguoussurfaces of the nested concentric cylinders are threaded and engage eachother so the vessel, the cover, the sealing cylinder, and the plungercan move with respect to each other to provide the desired samplingfunction. The plunger and the vessel have apertures in their respectivewalls which align so that fluid can flow through the plunger and intothe vessel when the sealing cylinder is retracted and the pistonassembly is inserted into the fluid flow. Once the sample has flowedinto the vessel, the sealing cylinder is advanced to close the aperturesand clean solid materials from the seating surfaces around the apertureson the vessel. The cover is also advanced to close the apertures but thecover is iso lated from the fluid by a flange so that the cover is notcontaminated on its outside surface by the fluid. Once the vessel issealed off and covered, and the piston assembly has been retracted, thevessel and cover can be removed as a unit from the piston assembly fortransfer or storage of the sample.

The sampler thus provides a safe, contaminant free container with aspecific volume of fluid. The operation is unaffected by the presence ofsolid matter in the fluid. The sampler does not disrupt the systembetween sample operations.

Further objects, features and advantages of this invention will becomeapparent from a consideration of the following description, the appendedclaims, and the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view ofthe fluid sampling device of this invention installed on a conduit forsampling fluid flowing therein;

FIG. 2 is an enlarged sectional view of the device as seen along line 22of FIG. 1 and showing the device in its loaded configuration;

FIG. 3 is a cross sectional view similar to FIG. 2 and shows the devicein its ready configuration;

FIG. 4 is a cross sectional view similar to FIG. 2 and shows the devicein its engaged position; and

FIG. 5 is a cross sectional view similar to FIG. 2 and shows the devicein its sample position.

DESCRIPTION OF THE PREFERRED EMBODIMENT Before explaining the presentinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction andarrangement of parts illustrated in the accompanying drawings, since theinvention is capable of other embodiments and of being practiced orcarried out in various ways. Also it is to be understood that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation.

Referring to the drawings, the fluid sampler 10 of this invention isshown in FIG. 1 attached to a conduit 12 for taking samples of fluidflowing in the conduit either under pressure or by gravity. The device10 has a hollow body 14 which attaches to the conduit 12 to form aT-section with the conduit 12. The hollow body 14 has a bore 16, asshown in FIG. 2, which communicates with the conduit 12 at essentially aright angle to the center line of conduit 12.

The device 10 also includes a piston assembly 18 which is slidablysupported for reciprocation within the bore 16. A retaining ring 19 isthreaded onto the hollow body 14 to retain the piston assembly 18 withinthe bore 16. The piston assembly 18 includes a plunger 20 which isessentially cylindrical and has a smooth external surface 22 for slidingwithin bore 16. The plunger 20 is sealingly supported in the bore 16against leakage by means of sealing rings 24. The plunger 20 has a lowerend 28 with a concave surface 30 which forms a part of the conduit 12when the piston assembly 18 is retracted, thus leaving the conduitopening free and unobstructed. The plunger 20 is hollow and has athreaded internal surface 32. A short internal cylinder 34 extendsupward from the lower end 28. The short cylinder 34 has internal andexternal threaded surfaces 36 and 38 respectively. The purpose of theshort cylinv der 34 will be explained presently. The plunger 20 also hasside openings 40 transversely aligned with each other (FIGS. 2 and 5),only one of which is shown in the drawings. The piston assembly 18 alsoincludes a sealing cylinder 42 with internal and external threadedsurfaces 44 and 46, respectively, which is nested within the plunger 20so that relative rotation between the plunger 20 and the sealingcylinder 42 results in relative axial displacement. A collar 43,attached to one end 45 of the sealing cylinder 42, is provided so thatthe sealing cylinder 42 can be rotated by manipulation of the collar 43.The sealing cylinder 42 has an inwardly extending annular flange 48 nearits lower end. The annular flange 48 has an internal threaded surface50. When the sealing cylinder 42 is in its lowest position as shown inFIG. 2, the annular flange 48 is seated against the top of the shortcylinder 34 and the threaded surfaces 36 and 50 form a continuous threadbore 52.

The device also includes a cover 54 in the form of a hollow cylinderwith internal and external threaded surfaces 56 and 58, respectively,which is nested within the sealing cylinder 42 above the annular flange48 so that relative rotation between the sealing cylinder 42 and thecover 54 results in relative axial displacement. A collar 55, attachedto one end 57 of the cover 54, is provided so that the cover 54 can berotated by manipulation of the collar 55. When the cover 54 is in itslowest position as shown in FIG. 2, it is seated against the annularflange 48 and its internal surface 56 aligns with surface 50 of theannular flange 48 to form an extension of continuous thread bore 52.

The device 10 also includes a vessel 60 in the form of a cylinder withexternal threaded surface 62 sized to be threaded into the internalthreaded surface 56 of cover 54 and continuous thread bore 52. A collar61, attached to one end 63 of the vessel 60, is provided so that thevessel 60 can be rotated by manipulation of the collar 61. The vessel 60has an internal cylinder 61 with transversely aligned inlet ports 64,only one of which is shown in the drawings. The chamber 61 is configuredso that it is larger than ports 64, thus forming faces 65 inside thechamber 61 around each port 64. The inlet ports 64 are situated so as toalign with side openings 40 when the vessel 60 is in its lowestposition, as shown in FIGS. 3-5. In this lowest position, the externalthreads 62 of vessel 60 are threaded into the internal threads 36 ofshort cylinder 34. A seal is thus provided between the fluid in conduit12 and the bottom surface 66 of vessel 60 which is seated againstseating surface 68 on the lower end 28 of plunger 20.

In operation, assume that the device 10 is in its loaded configurationas shown in FIG. 2 in which the plunger is retracted and the sealingcylinder 42 and the cover 54 are in their lowest position to form thecontinuous thread bore 52. The vessel 60 is then rotated so as to threadit downwardly to a position in which its bottom surface 66 is seatedagainst the seating surface 68 on lower end 28 of the plunger 20. Thedevice 10 is now in its ready configuration as shown in FIG. 3. A forceis then applied to the plunger 20 so as to move the piston assembly 18downwardly into the conduit 12 so as to project the plunger 20 into thefluid in the stream to be sampled. The device 10 is now in its engagedposition as shown in FIG. 4. In this position of the device 10, fluid inthe conduit 12 cannot enter the chamber 61 in the vessel 60 because thesealing cylinder 42 overlies the inlet ports 64 for the chamber 61.

The sealing cylinder 42 is then threaded upwardly in the plunger 20,without moving the vessel 60 or the plunger 20, so as to simultaneouslyraise both sealing cylinder 42 and cover 54 to place the device 10 inits sample position as shown in FIG. 5. In this position of the device10, fluid in the conduit 12 can flow into the vessel chamber 61 throughthe aligned side openings 40 and inlet ports 64 in the plunger 20 andthe vessel 60 respectively.

After the expiration of a time period sufficient to fill the chamber 61,the sealing cylinder 42 and the cover 54 are threaded downwardly to thepositions shown in FIG. 4 in which they close and seal the inlet ports64. During movement of the cylinder 42 and the cover 54 along theexternal threaded surface 62 of the vessel 60, the cover 54 and thesealing cylinder 42 act also to clean and remove all foreign materialfrom the external surface 62 of the vessel 60. It is to be noted thatthe external threaded surface 58 of the cover 54 and the bottom surface66 of the vessel 60 have at all times been prevented from contactingfluid in the conduit 12.

After the inlet ports 64 have been closed and sealed by the sealingcylinder 42, the piston assembly 18 is retracted to the position shownin FIG. 3. The vessel 60, filled with fluid from conduit 12 is thenrotated upwardly to the position shown in FIG. 2 in which the inletports 64 are sealed by the cover 54. The cover 54, supporting the vessel60, is then rotated upwardly out of the sealing cylinder 42 and removedfrom the piston assembly 18. The fluid in the chamber 61 can then bestored or transferred without any danger that the fluid in the chamber61 will be contaminated or exposed. During storage and transfer, thecontainer formed by the vessel 60 and the cover 54 is sealed and theexternal surfaces of the container are free of contamination by thefluid in the conduit 12 so that the container can be freely handled.

A second cover 54, supporting another vessel 60, can then be threadedinto the sealing cylinder 42 and the above sequence can be repeated whendesired to obtain another sample of fluid from conduit 12.

What is claimed is:

l. Fluid sampling apparatus for extracting a discrete sample of fluidfrom a fluid containing member, said apparatus comprising a plungerhaving an axis, means supporting said plunger for movement in adirection axially thereof between a retracted position and a positionprojecting into said fluid containing member, said plunger having a sideopening therein, a vessel having an internal chamber and side entranceport means communicating therewith, means mounting said vessel in saidplunger for movement in a direction extending axially of said plunger toa position in which said port means communicates with said plungeropening so that fluid can flow into said chamber in said projectingposition of said plunger, and means on said vessel operable to closesaid port means and support said vessel for removal from said plunger.

2. The fluid sampling apparatus that is defined in claim 1, wherein saidmeans supporting said plunger is a hollow body member having anessentially cylindrical bore and said vessel, said plunger, and saidmeans mounting said vessel in said plunger are essentially cylindricalin shape, are nested within each other and within said bore, and areaxially movable with respect to each other.

3. Fluid sampling apparatus according to claim 2 wherein said fluidcontaining member is a conduit of substantially circular cross sectionhaving an axis extending normal to said plunger axis, said plungerhaving a concave face closing the lower end of said body member bore insaid retracted position of said plunger.

4. Fluid sampling apparatus according to claim 1 wherein said meansmounting said vessel in said plunger includes a cylindrical sealingmember arranged in a removable covering relation with said vesselsupport means so as to protect said vessel support means against Contactwith said fluid.

5. The fluid sampling apparatus that is defined in claim 4, wherein saidplunger is hollow and cylindrical in shape and has a threaded bore witha closed end and an open end, said sealing member is hollow andcylindrical in shape and has a threaded external surface engageablewithin said threaded bore of said plunger and a threaded internal borewith both ends thereof open, said vessel support means is hollow andcylindrical in shape and has a threaded external surface engageablewithin said threaded bore of said sealing member and a threaded borewith both ends thereof open, and said vessel has a threaded externalsurface engageable within said threaded bore of said vessel supportmeans.

6. The fluid sampling apparatus that is defined in claim 5 wherein saidport means and said side opening are in communication when said vesselis seated against said closed end of said plunger.

7. Fluid sampling apparatus according to claim 6 wherein said closed endof said plunger has an internally threaded projection aligned with theinternally threaded bore of said vessel support means so that saidvessel can be threaded into said internally threaded projection to astop position engaged with said closed end.

8. The fluid sampling apparatus that is defined in claim 7 wherein saidsealing member has a radially inwardly directed flange having a threadedinternal surface aligned with and positioned between said internallythreaded projection on said closed end of said plunger and the threadedbore in said vessel support means.

9. The fluid sampling apparatus that is defined in claim 8 wherein saidvessel is adapted for retraction into said support means so that saidsupport means and said vessel can be removed as a unit from saidplunger.

1. Fluid sampling apparatus for extracting a discrete sample of fluidfrom a fluid containing member, said apparatus comprising a plungerhaving an axis, means supporting said plunger for movement in adirection axially thereof between a retracted position and a positionprojecting into said fluid containing member, said plunger having a sideopening therein, a vessel having an internal chamber and side entranceport means communicating therewith, means mounting said vessel in saidplunger for movement in a direction extending axially of said plunger toa position in which said port means communicates with said plungeropening so that fluid can flow into said chamber in said projectingposition of said plunger, and means on said vessel operable to closesaid port means and support said vessel for removal from said plunger.2. The fluid sampling apparatus that is defined in claim 1, wherein saidmeans supporting said plunger is a hollow body member having anessentially cylindrical bore and said vessel, said plunger, and saidmeans mounting said vessel in said plunger are essentially cylindricalin shape, are nested within each other and within said bore, and areaxially movable with respect to each other.
 3. Fluid sampling apparatusaccording to claim 2 wherein said fluid containing member is a conduitof substantially circular cross section having an axis extending normalto said plunger axis, said plunger having a concave face closing thelower end of said body member bore in said retracted position of saidplunger.
 4. Fluid sampling apparatus according to claim 1 wherein saidmeans mounting said vessel in said plunger includes a cylindricalsealing member arranged in a removable covering relation with saidvessel support means so as to protect said vessel support means againstcontact with said fluid.
 5. The fluid sampling apparatus that is definedin claim 4, wherein said plunger is hollow and cylindrical in shape andhas a threaded bore with a closed end and an open end, said sealingmember is hollow and cylindrical in shape and has a threaded externalsurface engageable within said threaded bore of said plunger and athreaded internal bore with both ends thereof open, said vessel supportmeans is hollow and cylindrical in shape and has a threaded externalsurface engageable within said threaded bore of said sealing member anda threaded bore with both ends thereof open, and said vessel has athreaded external surface engageable within said threaded bore of saidvessel support means.
 6. The fluid sampling apparatus that is defined inclaim 5 wherein said port means and said side opening are incommunication when said vessel is seated against said closed end of saidplunger.
 7. Fluid sampling apparatus according to claim 6 wherein saidclosed end of said plunger has an internally threaded projection alignedwith the internally threaded bore of said vessel support means so thatsaid vessel can be threaded into said internally threaded projection toa stop position engaged with said closed end.
 8. The fluid samplingapparatus that is defined in claim 7 wherein said sealing member has aradially inwardly directed flange having a threaded internal surfacealigned with and positioned between said internally threaded projectionon said closed enD of said plunger and the threaded bore in said vesselsupport means.
 9. The fluid sampling apparatus that is defined in claim8 wherein said vessel is adapted for retraction into said support meansso that said support means and said vessel can be removed as a unit fromsaid plunger.